Nowadays, quick-opening doors made out of an element of canvas or other type of flexible laminar element, secured by its upper end to a motor-driven drum which according to the rotation sense, establishes the winding or unwinding of the canvas, putting the same in a opening position or a closing position of door, are widely known.
It is also known in this type of quick-opening doors that canvas has in its lateral ends vertical alignments of abutment elements which are guided within vertical uprights of the door during the vertical displacement, upwards or downwards, of the sheet element being dimensioned said abutment elements and vertical uprights to permit that the abutment elements may release the uprights when the canvas receives a frontal push of a certain intensity, thus preventing its severance.
It is also known in this type of quick-opening doors to incorporate in the the upper area of the vertical uprights, of guides which have the objective to automatically return the abutment elements towards the internal region of the uprights once the canvas has been disassembled due to a frontal blow. In this way, the self-repair of the door is obtained making it unnecessary to resort to the intervention of a technical service or specialized personal.
In some industrial installations, it is usual that these type of quick-opening doors suffer repetitive frontal blows, by the approximation of vehicles to an excessive speed, or by the fact that the height of the load transported by the trolleys or vehicles is such that the door does not have enough time to reach its maximum degree of opening, nor the necessary height to permit that the load may pass under the canvas.
Given the fact that the requirements and conditions for the operation of the quick-opening doors are not the same in different types of industry using them, it is difficult to determine what are the reasons originating that the canvas of the door receives repetitive blows which provoke the release of the abutment elements from the guides of the vertical uprights.
This lack of information prevents to determine the reason for repeated incidences that if produced in a high frequency may be the reason for the accelerated spoilage of the canvas or abutment elements making necessary its substitution or repair by the manufacturer or pertinent technical services; therefore it also hampers the modification of the operation regime to make it to work according to parameters capable of preventing or reducing the frequency of incidences.
Another drawback of this type of doors is the difficulty to obtain the correct adjustment between the abutment element of the canvas and the vertical uprights to obtain the release of the abutment elements, preventing the severance of the canvas, when the door suffers a blow; and to make this adjustment adequate in order that the abutment elements do not release the vertical uprights when the canvas is submitted to efforts of lesser intensity which would not break the canvas, such as the push provoke by the wind.
This drawback is determined by the fact that the canvas, when receiving a frontal blow, curves toward the opposed side forming its ends an angle in respect of the means provided in the vertical uprights for the guidance of the abutment elements, which modifies the effort necessary in order that the abutment elements free themselves from the uprights of the frame of the door.
The inventor does not known the eventual existence of prior art to give a solution to the above stated problems.